8 9
Pairing the power meter
The power meter must be connected or “paired” to the cycle computer or
mobile device (collectively referred to as display units) according to the display
manufacturer’s instructions. Each power meter has a unique ANT+ device ID
and a unique Bluetooth ID. During the pairing process the applicable device ID
is recorded by the display and will be used to communicate with the
corresponding power meter. The ANT+ ID number is printed on the back of
the power meter and also supplied with the documentation. The Bluetooth ID
is recognized and displayed by the Bluetooth device during the pairing
process. Once paired to the power meter, ride data (Watts and RPM) will be
transmitted from the power meter to the display unit. Other important
functions such as resetting the power meter’s zero oset will also be enabled
through the display unit. Both the ANT+ and Bluetooth IDs are
permanently assigned to the power meter and are not aected by
changing the power meter battery.
ANT+: Ensure the power meter has a fully charged CR2032 battery properly
installed. Rotate the crank arm one time to ensure the power meter is awake
and ready to communicate. Follow the ANT+ device manufacturer’s
instructions for pairing a power meter to the display unit. The procedures may
vary between manufacturers.
Bluetooth Smart: Ensure the power meter has a fully charged CR2032 battery
properly installed. Rotate the crank arm one time to ensure the power meter is
awake and ready to communicate. Follow the Bluetooth Smart Ready (4.0)
device manufacturer’s instructions for pairing a power meter to the display
unit. The procedures may vary between manufacturers.
Zero oset calibration
The zero oset calibration is an important feature of the power meter that
resets the zero oset value for the power meter sensors. There are physical and
environmental conditions that may aect the zero oset value and there are
methods both manual and automatic that will adjust this value to
accommodate for the changing physical and environmental condition. The
zero oset of the power meter is essentially the sensor reading or values
measured when the power meter has no pedaling load (torque) applied. The
act of calibrating the zero oset causes the power meter to measure the value
at zero load and then records this value as the baseline for power
measurement. Loads applied while pedaling will then be measured as torque
and used by the sensor to determine power in Watts. The zero oset value can
be aected by the installation of the crank arm and the tightening of the
securing hardware. The torque applied to the securing hardware can impart
some strain into the crank material that is easily accounted for by manually
calibrating the zero oset. Any time the power meter is removed from the bike
and reinstalled the zero oset should be calibrated.
Ambient temperature shifts can also aect the zero oset to some extent. To
ensure maximum accuracy it is advisable to manually calibrate the zero oset
before each ride. The power meter utilizes automatic temperature sensors to
compensate for temperature changes that take place during the ride. This is
done automatically while you ride and you need not take any further steps to
calibrate the sensor during the ride.
How to calibrate the zero oset
Calibrating the zero oset is a function controlled by the cycle computer or
mobile device (display units) paired to the power meter. Please note that some
device manufacturers refer to the step of resetting the zero oset as
“calibration”. When paired to a compatible ANT+ cycle computer or Bluetooth
Smart mobile device, the power meter and display units are in two-way
communication. The display unit can send a command to the power meter to
calibrate the zero oset value and in some cases the resulting zero oset value
will be sent back from the power meter to the display unit and be shown on the
screen. Please note the displayed zero oset value will NOT be zero but rather
a number that corresponds to the measurement taken by the sensor.The
display units will also indicate if the procedure was successful or failed.